Photographic couplers



United States Patent Oflice 3,457,077 Patented July 22, 1969 3,457,077 PHOTOGRAPHIC COUPLERS Walter Puschel, Leverkusen, and Karl-Wilhelm Schranz,

Opladen, Germany, assignors to Agfa-Gevaert Aktiengesellschaft, Leverknsen, Germany, a corporation of Germany No Drawing. Filed May 18, 1966, Ser. No. 550,904 Claims priority, application Germany, May 26, 1965,

49,318 Int. Cl. G03c 1/40 US. Cl. 96-100 4 Claims ABSTRACT OF THE DISCLOSURE The invention relates to photographic materials which contain acyl monohydrazone couplers that couple with developer oxidation products of silver halide developers to form colorless compounds.

The photographic use of organic compounds which react colored direct positive images which are, however, of limited utility since the dyes produced by that process are only weakly colored. The color of those images sufiices only for the production of color masks. A process for the production of colored direct positive images according to the principle described in the aforementioned German patent would per se be extremely advantageous in comparison with the known direct-positive processes. Such a process would be superior to the known reversal films, because the processing would be much more simple; the second exposure and the second development would then be superfluous. 7

Another direct positive process is the so-called silver dye bleaching process. Layers which are colored with azo dyes are used for this purpose. Because of the absorption of light, the sensitivity of those layers does not match practical requirements.

British Patent No. 590,637 also describes cyan acetyl color couplers which are, substituted with a monohydrazone grouping and which react in known manner with oxidized color-forming developers to form a dyestuff.

German Patent No. 1,175,072 describes photographic materials which contain usual color couplers that react following formula also couple with the oxidation products of photographic developers to form colorless products. The compounds according to the present invention correspond to the following general formula:

i r X (Y) ,r-C-C==l lNII1 I in which X and X represent organic groups capable of mesomerism for example, olefinically unsaturated aliphatic groups such as vinyl, butadienyl, aromatic groups such as phenyl or naphthyl, or heterocyclic systems of aromatic structure, for example, furyl, thienyl, and pyridyl. These groups, the aryl radicals in particular, may optionally be substituted, for example, by C1, SO H, COOH, alkyl with up to 20 carbon atoms and preferably with 12-18 carbon atoms, aryl such as phenyl or naphthyl, N0 0H, lower alkoxy, phenoxy, NH or substituted amino groups. X can also be an alkyl group having up to 17 carbon atoms. Y represents the grouping in which R represents hydrogen, alkyl, preferably methyl, ethyl or propyl or aryl, preferably phenyl. R represents hydrogen, alkyl preferably alkyl having up to 5 carbon atoms, aryl, preferably phenyl, cycloalkyl, preferably cyclohexyl, aralkyl, preferably phenylalkyl, such as benzyl, phenyl ethyl or styryl, or heterocyclic groups, such as 'furyl, furylidenyl, indolyl, pyridyl, thienyl, thiazolyl benzthiazolyl, imidazolyl, oxazolyl, benzimidazolyl, benzoxazolyl, pyrazolyl or quinoazolyl or the groups in which R and R represent hydrogen, alkyl, preferably with up to 20 carbon atoms, aryl, in particular phenyl,

r or naphthyl, phenylalkyl such as benzyl or phenylethyl,

or 5- or 6-membered cycloaliphatic or heterocyclic rings, such as benzthiazolyl or benzimidazolyl or R and R together with the nitrogen atom may represent the ring members required .to complete a 5- or 6-membered heterocyclic ring optionally with further hetero atoms, for example, a morpholine ring. R X and Y may together represent the ring members required to complete a heterocyclic or isocyclic ring such as piperidine or pyrolidine, whilst the index n represents 0 or an integer from 1 to 3. The compounds can also have the X as a OH=CH- bridge connecting two portions, each conforming to the balance of the general formula.

The following compounds, for example, are suitable:

m m 0 O s S H N N N k H F M H m CHO P. J "m a v m 0 w w 5 m w H m m 0 S s H m H 0 CH0 7 H r N N m 7 Y 4 CH0 w m m a a H C H H m n u O w H w s m "m 0H0 H w o H O O a NI S SI H O 0 H N- S O H 1 4 H H N a m w m H 7 JUNO JQMIIO nw O. S H m n v 0 O H 0 5 O 5 C v 2 2 3 3 um 0 |S m m 3 w m ,w 70 M 0 v a. m o m w s H J w C 0 H N N H O N k N m. c c w s m H H o H 1 W CH0 m 5 01 m Q 0311 OaH SOaH cc. of methanol and the resulting mixture is dissolved in 200 cc. of 3% by weight sodium hydroxide solution. The solution is left standing overnight, and then mixed with a diazonium salt solution of 44 g. of 4-N,N-methylo ctadecylaminoaniline-3-sulfonic acid, prepared by conventional methods. A reddish-yellow deposit is obtained which, after washing with water, is dried in vacuo. M.P. above 300 C. (decomp).

Acylhydrazones are also obtained by directly coupling a diazonium salt with an acetyl or benzoylacetic ester derivative, and by subjecting the resulting dye to cleav age. For example, compound 3 can be prepared as fol lows:

11 g. of aniline-4-sulfonic acid are dissolved in 45 cc. of 2 N sodium hydroxide solution, and the resulting solution is diluted with 50 cc. of water. When solution is complete, 6.5 g. of sodium nitrite are added, and the resulting mixture is added dropwise at 0 to 5 C. to a mixture of cc. of concentrated hydrochloric acid and 15 cc. of

0 Water. After eliminating the nitrite excess, the solution is buffered with 10 g. of sodium acetate and mixed at room temperature with 18 g. of stearoyl acetic ester which, together with 18 g. of sodium acetate, has been dissolved in 300 cc. of methanol. The precipitate is suction-filtered, dried in vacuo and recrystallized from methanol. M.P. 106-107 C.

Saponification and decarboxylation of the resulting compound:

6 g. of the resulting dye are dissolved at elevated temperature in 40 cc. of n-propanol and 100 cc. of 2 N potassium hydroxide solution, and the resulting solution is refluxed for half an hour. After cooling, the solution is neutralized with acetic acid, suction-filtered and recrystallized from methanol. M.P. 168-169" C.

The preparation of the acyl formazanes is also known from the literature [e.g., Chem. Ber., 24 (3262)]. Thus, symmetrical formazanes may be prepared in a manner similar to that described above by reacting one mole of acylacetic acid with 2 mols of a diazotized amine. In order to obtain mixed acylforrnazanes, the following procedure is adopted: A corresponding diazonium salt is coupled with a monohydrazone of a diacyl compound, for example, compound 5 can be prepared as follows:

g. of 4-aminoanisole-(2)-sulfonicacid are dissolved in 200 cc. of water and 50 cc. of a 2 N solution of soda in the presence of 7 g. of sodium nitrite. The resulting mixture is introduced atO to 5 C. into a mixture of 5 cc. of concentrated hydrochloric acid and 20 cc. of water, after which the nitrite excess is eliminated. The diazonium salt solutionis mixed at C. with a solution of 4.6 g. of compound 3 in 300 cc. of methanol, 10 cc. of cone. sodium hydroxide solution and cc. of water. Stirring is continued for half an hour at room temperature, after which the product is acidified with hydrochloric acid to a pH from 1 to 2. If desired, precipitation may be accelerated by the addition of a saturated solution of sodium chloride. The product is suction-filtered and dried in vacuo. M.P. above 300 C.

The phenylglyoxylacid amide aryl hydrazones illustrated by the preceding formulae can be prepared by methods described in the literature, for example:

'R. G. Dubenko, R. S. Pelkis Ziobsch. Chim. 33, 3917- 3920, (1963), No. 12; r I

R. G. Dubenko, P. S. Pelkis Z.obsch. Chim. 34, 679- 682, (1964), No. 2;

Compound No. 20 as listed in the table is prepared as follows:

9.3 g. of aniline are added to cc. of half-concentrated hydrochloric acid, after which a solution of 8 g. of sodium nitrite in 20 cc. of water is added dropwise at 0 C.

with stirring and cooling. After stirring for another 15 minutes, the resulting diazonium salt solution is added to an acetate buffer consisting of 90 g. of soda and 450 cc. of glacial acetic acid, followed after stirring for another 15 minutes by the addition of a solution of 15 g. of w-chlOrO- acetophenone in 100 cc. of glacial acetic acid. Stirring is continued for another 3 hours at approximately C., after which the product is left standing overnight, suction filtered and the filtrate washed liberally with water and dried. Yield: 9 g. M.P. l3l132 C.

4.25 g. of this phenylglyoxyl acid chloride aryl hydrazone are suspended in 50 cc. of alcohol, and 3.5 g. of morpholine are added to the resulting suspension with stirring. After standing for 48 hours, the suspension is suction-filtered, washed with water and alcohol and recrystallized from alcohol. Yield: 3.5 g., M.P. 132-133 C.

By virtue of their properties and the properties of their coupling products, the compounds according to the invention may be divided up into two groups:

(1) Compounds of group 1.The acylhydrazones of this group are colored. Their color remains unaffected by oxidizing color-photographic baths, that is to say there are no changes in color during photographic processing in contrast to the osazones described in German Patent No. 1,083,125. During photographic processing, these substances react to form colorless secondary products at those areas affected by light. A direct positive color-image is obtained.

(2) Compounds of group 2.These are colorless and remain colorless even after photographic processing. Their behaviour during development would appear to indicate, however, that they too react with oxidized color developers to form colorless coupling products.

By virtue of this behaviour, the compounds according to the invention are interesting in many respects from the photographic point of view. For example, the compounds of group 1 may be used as masks in color-photographic materials, or for the production of colored direct-positive images. The compounds of group 2 which remain colorleess throughout processing, may be used as so-called white or colorless couplers for inhibiting color fogging or for improving color definition. They correspond in their functions to the compounds described in British Patents Nos. 861,138 and 914,145.

The compounds according to the invention are distinguished by their particularly smooth and quantitative reaction with the developer oxidation products.

Thecommon photographic processing baths are suitable for the direct reversal process according to the invention. Examples of some of the baths are set out below:

DEVELOPER A G. 4-amino-N,N-diethylaniline sulphate -1 2.5 Anhydrous sodium sulphite 1.0 Potassium bromide 1.0

Potassium carbonate 75.0 Water, 1 liter.

The 4-aminodiethylaniline of the solution specified in A is replaced by 5 g. of 4-amino-N,N-butyl, w-sulfobutyl aniline.

The 4-aminodiethylaniline of the solution specified .in A is replaced by 4 g. of 1-phenyl-4-aminopyrazolone-3-carboxylic acid amide.

G. p-methylaminophenol 8.0 Anhydrous sodium sulphite 2.0 Potassium carbonate 50.0 Potassium bromide 1.0

Water, 1 liter.

G. l-phenylpyrazolidone-S 0.5 Hydroquinone 4.0 Anhydrous sodium sulphite 25.0 Anhydrous sodium carbonate 25.0 Potassium bromide 1.0

Water, 1 liter.

Suitable are also p-aminophenol developers, for example, the developer Agfa 10, which is described in the book of Dr. Eduard Schloemann, Photochemikalien und ihre Anwendung.

OX-IDIZING BATHS The chemical structure of the oxidizing agent is not especially critical and is selected according to the properties of the monohydrazone compound with which the oxidizing agent is to be reacted. Preferred are those agents and baths which are commonly used in color photographic processes for bleaching silver images. Suitable agents are potassium ferricyanide, potassium bichromate or complex compounds of 3-valent iron or cobalt with amino-polycarboxylic acids such as ethylenediamine tetraacetic acid, nitrilo triacetic acid or the like, which are described, for example, in German Patent No. 866,605. Suitable baths are, for example, a 20% by weight aqueous solution of potassium ferricyanide or a 10% by weight aqueous solution of potassium bichromate.

It is also possible to apply combined bleach-fixing baths, such as described in German Patent No. 866,605, Example 5.

FIXING BATHS Any desired photographic fixing baths can be used. The fixing agent, however, must not have reducing properties. Preferred are aqueous solutions of salts of thiosulfate, e.g., sodium thiosulfate, potassium thiosulfate or ammonium thiosulfate. The fixing agents can be used as about 20% by weight aqueous solutions.

It might be advantageous in certain cases to rinse the photographic material between the different processing steps. After the final rinsing, drying can be performed by means of conventional dryers for photographic materials at slightly raised temperatures.

The monohydrazones of the present invention are added to the light-sensitive silver halide emulsion layer in an amount of between 5 and 50 g. per kg. of emulsion, preferably 10-30 g. They can be incorporated into the emulsion layer in a dissolvable diffusion-resistant form.

According to another method, the monohydrazone couplers are first dissolved in an oily organic material, and this combination is dispersed in a finely divided state throughout the emulsion The monohydrazone compound according to the invention can also be used in those processes in which the so-called succesive colorant formation is applied. In this process the monohydrazone is incorporated into the developer composition in an amount of between 5 to 40 g. per liter. The successive reaction with the oxidation product of the developer in each of single layers of the multi-layer material is obtained by controlled penetration of the processing solution. For example, in an integral tripack it is possible by means of such a solution to develop the top layer of the material without affecting the lower emulsion if the time of development is carefully controlled. The silver halide of the light-sensitive layers used in accordance with the present invention consists of a silver chloride or silver bromide or mixtures thereof,

particular gelatin. It is also possible to use a mixture of several binding agents.

The light-sensitive layer may consist further of additives in accordance with the special requirements of the photographic elements, such as sensitizers or stabilizers. The silver halide emulsion can be optically sensitized with the common methincyanine, rhodacyanine or merocyanine dyes. Furthermore it is possible to apply silver halide emulsions which are chemically sensitized by sulfur compounds, complexes of noble metals, such as gold, palladium or iridium, or by polyethylen glycol or derivatives thereof.

Example 1 1.5 g. of compound 1 are made into a paste with cc. of methanol and the resulting paste is dissolved in 50 cc. of a 4% by weight sodium hydroxide solution. The solution is mixed with 100 cc. of a conventional silver halide emulsion. T he emulsion is applied to a suitable support, for example, an acetyl cellulose, polycarbonate or terephthalate film. The resulting layer is yellow in color. It is exposed to light and then developed in developer A. Following bleaching out of the image silver in a potassium ferricyanide bleaching bath with a pH of 5.5 and fixing, a direct-positive yellow image is obtained.

Example 2 Photographic silver halide layers are prepared as described in Example 1 with compounds 20, 21, 22, 23, 24, 25 and 26. The resulting layers are developed in developer B. In each instance, yellowish to reddish-orange direct positive images are obained.

Example 3 1.5 g. of compound 7 are applied to a support as described in Example 1. Following exposure, the layer is developed in developer B. Bleaching is carried out in a potassium ferricyanide bleaching bath with a pH of 7.1. A yellow direct-positive image is obtained.

Example 4 The procedure of Example 1 is repeated with compounds 6, and 11. Development is carried out in developer B and bleaching in a 10% by weight solution of sodium bichromate. Red direct-positive images are obtained.

Example 5 The procedure of Example 1 is repeated with compounds 4, 5, 8, 9 and 19. Bleaching is carried out in a 10% by weight solution of potassium ferricyanide adjusted to pH 8.5 with sodium borate. Yellow direct-positive images are obtained.

Example 6 The procedure of Example 1 is repeated with compounds 13 and 16. -In this instance, bleaching is carried out in a combined bleaching and fixing bath of the type described in German Patent No. 866,605. A yellow directpositive image is obtained.

Example 7 The procedure of Example 1 is repeated with compound 4. In this instance, development is carried out in developer C. A yellow direct-positive image is obtained.

Example 8 The following silver halide layers are applied to a film support in the order in which they are listed:

(1) A green-sensitive silver bromide emulsion containing 8 g. of 1-(4'-sulphophenyl)-3-heptadecyl-5-pyrazolone;

(2) A green-sensitive silver halide emulsion layer containing 8 g. of compound 4. A bath of the following composition is used for development:

G. 4-amino-N,N-butylbutane-sulfo-aniline 5.0 Sodium sulfite anhydrous 1.0 Potassium carbonate 75.0 Water, liter.

Bleaching is then carried out with a 20% by weight solution of potassium ferricyanide, followed by fixing in a bath comprising a 20% aqueous solution of sodium thiosulfate. A negative, purple image is obtained in layer 1 and a positive yellow image in layer 2 which compensates for the extra absorption of the purple-colored negative is obtained.

What is claimed is:

1. In photographic silver halide emulsions containing couplers that couple with oxidation products of color developers to form colorless compounds and have the formula X and X are organic mesomerizable groups,

n is zero or an integer from 1 to 3, and

R and R are hydrogen or hydrocarbyl, the improvement according to which the coupler has a group linking the (Y) with the 2. In photographic silver halide emulsions containing couplers that couple with oxidation products of color developers to form colorless compounds and have the formula X is an organic mesomerizable group, and

R is hydrogen or hydrocarbyl, the improvement according to which the coupler has its R II (I) connected to X (Y)u where X is also an organic mesomerizable group or alkyl having up to 17 carbon atoms,

n is zero or an integer from 1 to 3, and

R is also hydrogen or hydrocarbyl.

3. The combination of claim 2 in which X is a phenyl or naphthyl group.

4. The combination of claim 2 in which X is a furyl, thienyl or pyridyl group.

References Cited UNITED STATES PATENTS 3,186,840 6/1965 Puschel et al. 969 3,245,787 4/1966 Willems et al. 969 3,245,788 4/1966 Jaeken et al. 969 3,293,032 12/1966 Jaeken et al. 9622 3,378,554 4/ 1968 Puschel et al. 260-240 3,384,484 5/1968 Schranz et al. 9653 NORMAN G. TORCHIN, Primary Examiner ALFONSO T. SURO PICO, Assistant Examiner US. Cl. X.R. 

